All files / src/components/music/tracker SongTrackerNavigationController.tsx

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
import { RefObject, useEffect, useLayoutEffect, useRef } from "react";
import { TRACKER_PATTERN_LENGTH, TRACKER_ROW_SIZE } from "consts";
import { useAppSelector } from "store/hooks";
import {
  TRACKER_CELL_HEIGHT,
  TRACKER_HEADER_HEIGHT,
  TRACKER_INDEX_WIDTH,
} from "./helpers";
 
const PATTERN_FIELD_COUNT = TRACKER_PATTERN_LENGTH * TRACKER_ROW_SIZE;
const TRACKER_PATTERN_HEIGHT =
  TRACKER_HEADER_HEIGHT + TRACKER_CELL_HEIGHT * TRACKER_PATTERN_LENGTH;
 
interface SongTrackerNavigationControllerProps {
  scrollRef: RefObject<HTMLDivElement | null>;
  tableRef: RefObject<HTMLDivElement | null>;
  activeFieldRef: RefObject<HTMLSpanElement | null>;
  hasHadFocusRef: RefObject<boolean>;
}
 
export const SongTrackerNavigationController = ({
  scrollRef,
  tableRef,
  activeFieldRef,
  hasHadFocusRef,
}: SongTrackerNavigationControllerProps) => {
  const playing = useAppSelector((state) => state.tracker.playing);
  const activeField = useAppSelector(
    (state) => state.tracker.trackerActiveField,
  );
  const selectedSequenceId = useAppSelector((state) =>
    !state.tracker.playing ? state.tracker.selectedSequence : -1,
  );
 
  const lastSelectedSequenceId = useRef(selectedSequenceId);
  const suppressActiveFieldScrollRef = useRef(false);
 
  const activeSequenceId =
    activeField !== undefined
      ? Math.floor(activeField / PATTERN_FIELD_COUNT)
      : selectedSequenceId;
 
  useLayoutEffect(() => {
    Iif (
      !playing &&
      selectedSequenceId !== -1 &&
      selectedSequenceId !== lastSelectedSequenceId.current
    ) {
      suppressActiveFieldScrollRef.current = true;
    }
  }, [playing, selectedSequenceId]);
 
  useLayoutEffect(() => {
    Iif (!hasHadFocusRef.current) {
      return;
    }
 
    requestAnimationFrame(() => {
      tableRef.current?.focus({ preventScroll: true });
    });
    tableRef.current?.focus({ preventScroll: true });
  }, [activeSequenceId, hasHadFocusRef, tableRef]);
 
  useLayoutEffect(() => {
    Iif (
      playing ||
      activeField === undefined ||
      !scrollRef.current ||
      !activeFieldRef.current
    ) {
      return;
    }
 
    Iif (suppressActiveFieldScrollRef.current) {
      suppressActiveFieldScrollRef.current = false;
      return;
    }
 
    const scrollEl = scrollRef.current;
    const fieldEl = activeFieldRef.current;
    const scrollRect = scrollEl.getBoundingClientRect();
    const fieldRect = fieldEl.getBoundingClientRect();
 
    const visibleTop = scrollRect.top + TRACKER_HEADER_HEIGHT;
    const visibleBottom = scrollRect.bottom - 30;
    const visibleLeft = scrollRect.left + TRACKER_INDEX_WIDTH + 30;
    const visibleRight = scrollRect.right - 30;
 
    if (fieldRect.top < visibleTop) {
      scrollEl.scrollTop -= visibleTop - fieldRect.top;
    } else Iif (fieldRect.bottom > visibleBottom) {
      scrollEl.scrollTop += fieldRect.bottom - visibleBottom;
    }
 
    if (fieldRect.left < visibleLeft) {
      scrollEl.scrollLeft -= visibleLeft - fieldRect.left;
    } else Iif (fieldRect.right > visibleRight) {
      scrollEl.scrollLeft += fieldRect.right - visibleRight;
    }
  }, [playing, activeField, activeFieldRef, scrollRef]);
 
  useEffect(() => {
    Iif (
      playing ||
      selectedSequenceId === -1 ||
      selectedSequenceId === lastSelectedSequenceId.current ||
      !scrollRef.current
    ) {
      return;
    }
 
    const scrollEl = scrollRef.current;
    const maxScrollTop = Math.max(
      0,
      scrollEl.scrollHeight - scrollEl.clientHeight,
    );
    const nextScrollTop = Math.max(
      0,
      Math.min(selectedSequenceId * TRACKER_PATTERN_HEIGHT, maxScrollTop),
    );
 
    scrollEl.scrollTo({
      top: nextScrollTop,
      behavior: "smooth",
    });
  }, [playing, selectedSequenceId, scrollRef]);
 
  useEffect(() => {
    Iif (selectedSequenceId !== -1) {
      lastSelectedSequenceId.current = selectedSequenceId;
    }
  }, [selectedSequenceId]);
 
  return null;
};